1. Field of the Invention
The invention relates to a descent device, more particularly to a descent device which can control automatically the descending speed of a load carrier.
2. Description of the Related Art
Referring to FIG. 1, a cross sectional view of a conventional descent device 1, which is generally mounted on a tall building for the purpose of escape in the event of a fire, is shown to comprise a load carrier (not shown), a power-operated main rotating shaft 6 with a plurality of brake drums 7 fixed thereon, a manually-operated brake pedal 3, and a reel unit 102 which has a coil of cable 101 wrapped therearound and which is connected operably to the main rotating shaft 6. The coil of cable 101 has one end connected to and suspends the load carrier. When lowering the load carrier downward, the descending speed of the load carrier is faster as it approaches the ground. The descending speed is controlled by actuating of the brake pedal 3. As best illustrated, in order to reduce the descending speed of the load carrier, the brake pedal 3 is compressed against biasing action of a spring 4, wherein the brake shoe 5 will press against the brake drums 7, thereby providing friction to control the descent of the load carrier.
Some of the drawbacks that result from the use of the conventional descent device are as follows:
(I) There is no one to operate the brake pedal 3, when the last escapee wishes to lower himself to the ground. Thus, the load carrier moves at an uncontrolled speed and may result in injuries to the last escapee. PA1 (II) In times of .danger and confusion, the escapees seldom have the presence of mind to operate the brake pedal, thereby causing the load carrier to move at a relatively fast speed or to hang half-way to the ground.